Are there any downsides, then?
If anything, it's lead time.
Our exclusive process is competitive price-wise with inferior steel sleeving used by some builders, but our turnaround isn't as good. It's just the nature of the process.
Block has to be first machined, then sleeves made and fitted to the block. Those sleeves need to then be plated, installed, and finish honed. The very last step is the deck is surface ground to the correct finish for the supplied MLS head gaskets. This process takes on average 4-6 weeks.